Self-constituted is a description that is commonly used to describe a person who has created their own position of authority or power. There are a number of synonyms that can be used to describe the same concept, including self-appointed, self-made, self-proclaimed, self-named, and self-created. Each of these words implies that an individual has taken it upon themselves to establish a certain level of authority or influence, without necessarily being appointed or sanctioned by anyone else. These terms can be used to describe a wide range of situations, from individuals who have created their own businesses or organizations to those who have simply set themselves up as experts or leaders in a particular field.